1. Field of the Invention
The present invention relates to a manufacturing apparatus for manufacturing a coordinate detecting device.
2. Description of the Related Art
For example, as an input device for a computer system, a touch panel is known. A touch panel may be mounted on a display device, and, may be such that, a coordinate position on the display device is detected, and a detection signal according to the coordinate position may be obtained. Thus, the touch panel makes it possible to input the detection signal according to the coordinate position to the computer system directly, and thus, the touch panel makes it possible to carry out easy and intuitive input.
For a touch panel, various types such as a resistive film type, an optical type, a capacity coupling type, and so forth, are proposed. Among such touch panels, a touch panel of the resistive film type is common, which has a simple configuration and requires a simple control system. The resistive film type touch panel may be of a four-wire type, a five-wire type, an eight-wire type or of many different types to dispose electrodes on a resistive film.
Among these types, the five-wire type touch panel does not have a problem concerning edge sliding which may be a problem of the four-wire type touch panel and an eight-wire type touch panel. This is because, in the five-wire type touch panel, an electrically conductive film of an upper substrate disposed on an operating surface side is used only for reading an electric potential. Therefore, the five-wire type touch panel is used in a market which requires a tough operation environment or durability for a long term.
FIG. 9 depicts an example of a configuration of a five-wire type resistive film type touch panel. The five-wire type resistive film type touch panel 1 depicted in FIG. 9 includes an upper substrate 11 and a lower substrate 12. In the lower substrate 12, a transparent resistive film 22 is formed on the whole area of a glass substrate 21, and X-axis coordinate detecting electrodes 23, 24 and Y-axis coordinate detecting electrodes 25, 26 are formed on the transparent resistive film 22. In the upper substrate 11, a transparent resistive film 32 is formed on a film substrate 31, and a coordinate detecting electrode 33 is formed on the transparent resistive film 32.
In the five-wire type resistive film type touch panel 1, first, a voltage is applied between the X-axis coordinate detecting electrodes 23 and 24. As a result, an electric potential distribution occurs along an X-axis direction X1-X2 of the transparent resistive film 22 of the lower substrate 12. Then, by detecting an electric potential of the transparent resistive film 22 of the lower substrate 12 at a position at which the upper substrate 11 comes into contact with the lower substrate 12, it is possible to detect an X coordinate of the position at which the upper substrate 11 comes into contact with the lower substrate 12. Next, a voltage is applied between the Y-axis coordinate detecting electrodes 25 and 26. As a result, an electric potential distribution occurs along a Y-axis direction Y1-Y2 of the transparent resistive film 22 of the lower substrate 12. Then, by detecting an electric potential of the transparent resistive film 22 of the lower substrate 12 at a position at which the upper substrate 11 comes into contact with the lower substrate 12, it is possible to detect a Y coordinate of the position at which the upper substrate 11 comes into contact with the lower substrate 12.
At this time, in such a type of a touch panel, how the electric potential distribution can be created uniformly along each of the X-axis direction X1-X2 and the Y-axis direction Y1-Y2 of the transparent resistive film 22 of the lower substrate 12 may be a problem. As a method to solve the problem, Japanese Laid-Open Patent Application No. 10-83251 (referred to as a patent document 1) discloses a method of providing a plurality of stages of electric potential distribution correcting patterns in the periphery of a resistive film.
Japanese Laid-Open Patent Application No. 2001-125724 (referred to as a patent document 2) discloses a method of providing a common electrode which surrounds the periphery of an input surface. Japanese Laid-Open Patent Application No. 2007-25904 (referred to as a patent document 3) discloses a method of forming opening parts in an insulative film provided on a transparent resistive film, and providing an electric potential from the opening parts.
It is noted that, reducing a size of such a coordinate detecting device may be required because size reduction of an apparatus in which the coordinate detecting device is mounted is required. According to a coordinate detecting device disclosed in the patent document 1, it may be difficult to reduce a size of the coordinate detecting device since the plurality of stages of electric distribution correcting patterns are provided in the periphery of the resistive film as mentioned above.
In the method disclosed by the patent document 2 to provide a common electrode which surrounds the periphery of an input surface as mentioned above, an electric potential distribution of a transparent resistive film may be distorted unless a resistance ratio of the transparent resistive film and a pattern resistance is increased.
In the method disclosed by the patent document 3 to form opening parts in an insulative film provided on a transparent resistive film, although the above-mentioned two problems may be solved, a complicated manufacturing process may be required. Especially, a yield of product performance may degrade because of a possible variation of a material or a resistance value which may occur during manufacturing.